Timber structures - Strength graded structural timber with rectangular cross section - Part 1: General requirements

This European Standard specifies requirements for strength graded structural timber with rectangular cross-sections either visual or machine graded, shaped by sawing, planning or other methods and with cross-sectional dimensions complying with EN 336 (referred to as structural timber in the following clauses).
This European Standard includes provisions for test methods, Assessment and Verification of Constancy of Performance and marking of structural timber.
NOTE 1   For machine strength graded timber additional provisions for type testing (TT) are given in EN 14081-2 and for factory production control (FPC) in EN 14081-3.
NOTE 2   An acceptance procedure for verification of a lot is given in EN 14358 which may be used for a delivery of structural timber.
This European Standard identifies characteristics for which limits have to be given in visual grading standards.
This European Standard covers structural timber, untreated or treated against biological attack.
This European Standard does not cover:
-   timber treated by fire retardant products to improve its fire performance;
-   thermally and/or chemically modified timber;
-   structural finger jointed timber.

Holzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende zwecke mit rechteckigem Querschnitt - Teil 1: Allgemeine Anforderungen

Diese Europäische Norm legt Anforderungen an visuell oder maschinell nach der Festigkeit sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt fest, das durch Sägen, Hobeln oder andere Verfahren erzeugt wurde und Querschnittsmaße nach EN 336 aufweist (nachfolgend als „Bauholz für tragende Zwecke“ bezeichnet).
Die vorliegende Europäische Norm enthält Festlegungen für Prüfverfahren, die Bewertung und Überprüfung der Leistungsbeständigkeit sowie die Kennzeichnung von Bauholz für tragende Zwecke.
ANMERKUNG 1   Für maschinell nach der Festigkeit sortiertes Bauholz sind zusätzliche Festlegungen für die Typprüfung (TT) in EN 14081 2 sowie für die werkseigene Produktionskontrolle (WPK) in EN 14081 3 angegeben.
ANMERKUNG 2   Ein Annahmeverfahren für die Prüfung von Losen, das für Lieferungen von Bauholz für tragende Zwecke verwendet werden darf, ist in EN 14358 angegeben.
Diese Europäische Norm legt Sortiermerkmale fest, für die in den Normen zur visuellen Sortierung Grenzwerte anzugeben sind.
Diese Europäische Norm gilt für Bauholz für tragende Zwecke, das entweder unbehandelt ist oder gegen biologischen Befall behandelt wurde.
Diese Europäische Norm gilt nicht für:
—   Bauholz, das mit Feuerschutzmitteln behandelt wurde, um sein Verhalten bei Brandeinwirkung zu verbessern;
—   thermisch und/oder chemisch modifiziertes Bauholz;
—   keilgezinktes Bauholz für tragende Zwecke.

Structures en bois - Bois de structure à section rectangulaire classé pour sa résistance - Partie 1 : Exigences générales

La présente Norme européenne prescrit les exigences applicables au bois de structure à section rectangulaire classé soit visuellement soit par machine, profilé par sciage, rabotage ou d’autres méthodes, et ayant des dimensions minimales de section conformes à l'EN 336 (désigné comme bois de structure dans les articles suivants).
La présente Norme européenne comprend des dispositions relatives aux méthodes d'essai, à l'évaluation et la vérification de la constance des performances et au marquage du bois de structure.
NOTE 1   Pour le bois dont la résistance est classée par machine, des dispositions supplémentaires pour les essais de type (TT) sont spécifiées dans l'EN 14081-2 et pour le contrôle de production interne (CPU) dans l'EN 14081-3.
NOTE 2   Une procédure d’acceptation pour la vérification d’un lot est indiquées dans l’EN 14358 et celle-ci peut être utilisée pour la livraison de bois de structure.
La présente Norme européenne identifie, les caractéristiques pour lesquelles des limites sont établies dans les règles de classement visuel.
La présente Norme européenne couvre le bois de structure, non traité ou traité contre les attaques biologiques.
La présente Norme européenne ne couvre pas :
-   le bois traité par des produits ignifuges pour améliorer sa performance au feu ;
-   les bois modifiés thermiquement et/ou chimiquement ;
-   le bois avec aboutages à entures multiples.

Lesene konstrukcije - Po trdnosti razvrščen konstrukcijski les pravokotnega prečnega prereza - 1. del: Splošne zahteve

Ta evropski standard določa zahteve za vizualno in strojno razvrščen konstrukcijski les pravokotnega prečnega prereza po trdnosti, ki je oblikovan z žaganjem, struženjem ali z drugimi metodami in izpolnjuje zahteve standarda EN 336 glede najmanjših dimenzij prečnega prereza.
Ta evropski standard vključuje določbe za preskusne metode, ocenjevanje in preverjanje nespremenljivosti lastnosti ter označevanjem po trdnosti razvrščenega konstrukcijskega lesa.
OPOMBA: V standardu EN 14081-2 so za strojno razvrščen konstrukcijski les po trdnosti podane dodatne določbe za tipsko preskušanje (TT), v standardu EN 14081-3 pa za kontrolo proizvodnje v obratu (FPC).
Ta evropski standard opredeljuje lastnosti, za katere so podane omejitve v standardih za vizualno razvrščanje. Ta evropski standard obravnava pravokotni konstrukcijski les, zaščiten ali nezaščiten pred biološkimi dejavniki.
Ta evropski standard ne obravnava:
– lesa, obdelanega z zaščitnimi sredstvi proti ognju, ki izboljšujejo odpornost proti ognju;
– zobato spojenega lesa.

General Information

Status
Published
Publication Date
13-Oct-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
27-Aug-2019
Due Date
01-Nov-2019
Completion Date
14-Oct-2019

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SLOVENSKI STANDARD
SIST EN 14081-1:2016+A1:2019
01-november-2019
Nadomešča:
SIST EN 14081-1:2016
Lesene konstrukcije - Po trdnosti razvrščen konstrukcijski les pravokotnega
prečnega prereza - 1. del: Splošne zahteve

Timber structures - Strength graded structural timber with rectangular cross section -

Part 1: General requirements
Holzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende zwecke mit
rechteckigem Querschnitt - Teil 1: Allgemeine Anforderungen

Structures en bois - Bois de structure à section rectangulaire classé pour sa résistance -

Partie 1 : Exigences générales
Ta slovenski standard je istoveten z: EN 14081-1:2016+A1:2019
ICS:
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
91.080.20 Lesene konstrukcije Timber structures
SIST EN 14081-1:2016+A1:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 14081-1:2016+A1:2019
---------------------- Page: 2 ----------------------
SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2019
EUROPÄISCHE NORM
ICS 79.040 Supersedes EN 14081-1:2016
English Version
Timber structures - Strength graded structural timber
with rectangular cross section - Part 1: General
requirements

Structures en bois - Bois de structure à section Holzbauwerke - Nach Festigkeit sortiertes Bauholz für

rectangulaire classé pour sa résistance - Partie 1 : tragende zwecke mit rechteckigem Querschnitt - Teil 1:

Exigences générales Allgemeine Anforderungen

This European Standard was approved by CEN on 9 February 2016 and includes Amendment 1 approved by CEN on 14 May

2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14081-1:2016+A1:2019 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)
Contents Page

European foreword ............................................................................................................................................. 4

Introduction .......................................................................................................................................................... 5

1 Scope .......................................................................................................................................................... 6

2 Normative references .......................................................................................................................... 6

3 Terms and definitions ......................................................................................................................... 7

4 Symbols ..................................................................................................................................................... 8

5 Requirements for structural timber .............................................................................................. 9

5.1 Mechanical resistance ......................................................................................................................... 9

5.1.1 General ...................................................................................................................................................... 9

5.1.2 Visual strength grading ....................................................................................................................... 9

5.1.3 Machine strength grading .................................................................................................................. 9

5.2 Fire resistance (charring rate) .......................................................................................................11

5.3 Reaction to fire .....................................................................................................................................11

5.4 Release of dangerous substances ..................................................................................................12

5.5 Biological durability ...........................................................................................................................12

5.5.1 Structural timber without preservative treatment ................................................................12

5.5.2 Structural timber with preservative treatment .......................................................................12

5.6 Geometrical data .................................................................................................................................12

6 Assessment and verification of constancy of performance –AVCP ...................................13

6.1 General ....................................................................................................................................................13

6.2 Type testing ...........................................................................................................................................13

6.2.1 General ....................................................................................................................................................13

6.2.2 Test samples, testing and compliance criteria .........................................................................13

6.2.3 Test reports ...........................................................................................................................................14

6.2.4 Shared other party results ...............................................................................................................15

6.3 Factory production control (FPC) .................................................................................................15

6.3.1 General ....................................................................................................................................................15

6.3.2 Requirements .......................................................................................................................................15

6.3.3 Product specific requirements .......................................................................................................19

6.3.4 Initial inspection of factory and of FPC .......................................................................................20

6.3.5 Continuous surveillance of FPC ......................................................................................................20

6.3.6 Procedure for modifications ...........................................................................................................20

7 Marking ...................................................................................................................................................21

7.1 Marking methods ................................................................................................................................21

7.2 Information on the timber (method A) or on the package (method B) ...........................21

7.3 Information in the documents accompanying strength graded structural timber .....22

8 Environmental issues ........................................................................................................................23

Annex A (normative) Requirements for strength reducing characteristics for visual grading

standards ...............................................................................................................................................24

A.1 Limitations for strength-reducing characteristics ..................................................................24

A.1.1 Knots ........................................................................................................................................................24

A.1.2 Slope of grain ........................................................................................................................................24

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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)

A.1.3 Density and rate of growth .............................................................................................................. 24

A.1.4 Fissures .................................................................................................................................................. 25

A.2 Limitations for geometrical characteristics .............................................................................. 25

A.2.1 Wane ........................................................................................................................................................ 25

A.2.2 Warp ........................................................................................................................................................ 25

A.3 Limitations for biological characteristics .................................................................................. 26

A.4 Other characteristics ......................................................................................................................... 26

A.4.1 Reaction wood ..................................................................................................................................... 26

A.4.2 Other criteria ........................................................................................................................................ 26

Annex B (normative) Marking codes for species .................................................................................. 27

B.1 Marking codes for single species .................................................................................................. 27

B.2 Marking codes for species combination ..................................................................................... 28

Annex C (normative) Measurement of moisture content .................................................................. 30

C.1 General ................................................................................................................................................... 30

C.2 Measurement of moisture content of timber during production...................................... 30

Annex ZA (informative) Relationship of this European Standard with Regulation (EU)

No.305/2011 ........................................................................................................................................ 31

ZA.1 Scope and relevant characteristics .............................................................................................. 31

ZA.2 System of Assessment and Verification of Constancy of Performance (AVCP) ............ 33

ZA.3 Assignment of AVCP tasks ............................................................................................................... 33

Bibliography ....................................................................................................................................................... 36

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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)
European foreword

This document (EN 14081-1:2016) has been prepared by Technical Committee CEN/TC 124 “Timber

structures”, the secretariat of which is held by AFNOR.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by February 2020, and conflicting national standards

shall be withdrawn at the latest by May 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document includes Amendment 1, approved by CEN on 2019-05-14.
This document supersedes !EN 14081-1:2016".

The start and finish of text introduced or altered by amendment is indicated in the text by tags !".

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association, and supports essential requirements of EU Regulation n°305/2011.

For relationship with EU Regulation, see informative Annex ZA, which is an integral part of this

document.

EN 14081-4:2009 will be withdrawn and replaced by 5.1.3, paragraph 2 of this document.

Compared to EN 14081-1:2005+A1:2011, the following modifications have been made:

— new Clause 6 for Assessment and Verification of Constancy of Performance linked to the CPR;

— Annex ZA has been adapted to the CPR;

— new clauses on Fire Resistance, release of dangerous substances, geometrical data and

environmental issues have been added;
— marking codes for species combinations have been moved to Annex B;
— improvement of several definitions.
Other parts of the series of EN 14081 are:

— EN 14081-2, Timber structures - Strength graded structural timber with rectangular cross section -

Part 2: Machine grading; additional requirements for initial type testing;

— EN 14081-3, Timber structures - Strength graded structural timber with rectangular cross section -

Part 3: Machine grading; additional requirements for factory production control.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)
Introduction

There are basically two methods of strength grading: visual grading and machine grading.

Machine grading is in common use in a number of countries. The countries use two basic systems,

referred to as 'output control' and 'machine control'. Both systems require a visual override inspection

to cater for strength-reducing characteristics that are not automatically sensed by the machine.

Output control is suitable for use where the grading machines are situated in manufacturing units

grading limited sizes, species and grades in repeated production runs. This enables the system to be

controlled by testing timber specimens from the daily output. These tests, together with statistical

procedures, are used to monitor and adjust the machine settings to maintain the required strength

properties for each strength class. With this system it is permissible for machine approval requirements

to be less demanding and for machines of the same type to have non-identical performance.

Machine control was developed in Europe. Because of the large number of sizes, species and grades

used it was not possible to carry out quality control tests on timber specimens drawn from production.

Machine control relies, therefore, on the machines being strictly assessed and controlled, and on

considerable research effort to derive the machines settings, which remain constant for all machines of

the same type.

Visual grading is also in common use in a number of countries. There are many different visual strength

grading standards for timber in use in Europe. These have come into existence to allow for:

— different species or groups of species;
— geographic origin;
— different dimensional requirements;
— varying requirements for different uses;
— quality of material available;
— historic influences or traditions.

Because of the diversity of existing visual grading standards in use in different countries, it is currently

impossible to lay down a single standard for all Member States.

The requirements given in this European Standard on visual strength grading are therefore basic

principles, which should be followed when drawing up requirements for limits for some of the

characteristics.
The assignments to strength classes are based on grading reports.

When these grading reports are evaluated and approved by CEN/TC 124/WG2/TG1, they become

Approved Grading Reports (AGR) which are required for assigning visual grades to EN 1912 and for

machine control.
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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)
1 Scope

This European Standard specifies requirements for strength graded structural timber with rectangular

cross-sections either visual or machine graded, shaped by sawing, planning or other methods and with

cross-sectional dimensions complying with EN 336 (referred to as structural timber in the following

clauses).

This European Standard includes provisions for test methods, Assessment and Verification of Constancy

of Performance and marking of structural timber.

NOTE 1 For machine strength graded timber additional provisions for type testing (TT) are given in EN 14081–

2 and for factory production control (FPC) in EN 14081–3.

NOTE 2 An acceptance procedure for verification of a lot is given in EN 14358 which may be used for a delivery

of structural timber.

This European Standard identifies characteristics for which limits have to be given in visual grading

standards.

This European Standard covers structural timber, untreated or treated against biological attack.

This European Standard does not cover:
— timber treated by fire retardant products to improve its fire performance;
— thermally and/or chemically modified timber;
— structural finger jointed timber.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

EN 338, Structural timber — Strength classes

EN 350-1, Durability of wood and wood-based products — Natural durability of solid wood — Part 1:

Guide to the principles of testing and classification of the natural durability of wood

EN 350-2, Durability of wood and wood-based products — Natural durability of solid wood — Part 2:

Guide to natural durability and treatability of selected wood species of importance in Europe

EN 384, Structural timber — Determination of characteristic values of mechanical properties and density

EN 844-7, Round and sawn timber — Terminology — Part 7: Terms relating to anatomical structure of

timber

EN 844-9, Round and sawn timber — Terminology — Part 9: Terms relating to features of sawn timber

EN 844-10, Round and sawn timber — Terminology — Part 10: Terms relating to stain and fungal attack

EN 1310:1997, Round and sawn timber — Method of measurement of features

EN 1912, Structural Timber — Strength classes — Assignment of visual grades and species

EN 1995-1-2, Eurocode 5: Design of timber structures — Part 1-2: General — Structural fire design

---------------------- Page: 8 ----------------------
SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)

EN 13183-2, Moisture content of a piece of sawn timber — Part 2: Estimation by electrical resistance

method

EN 13183-3, Moisture content of a piece of sawn timber — Part 3: Estimation by capacitance method

EN 13238, Reaction to fire tests for building products — Conditioning procedures and general rules for

selection of substrates

EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification

using test data from reaction to fire tests

EN 13501-2, Fire classification of construction products and building elements — Part 2: Classification

using data from fire resistance tests, excluding ventilation services
EN 13556, Round and sawn timber — Nomenclature of timbers used in Europe

EN 13823, Reaction to fire tests for building products — Building products excluding floorings exposed to

the thermal attack by a single burning item

EN 14081-2, Timber structures — Strength graded structural timber with rectangular cross section —

Part 2: Machine grading; additional requirements for initial type testing

EN 14081-3, Timber structures — Strength graded structural timber with rectangular cross section —

Part 3: Machine grading; additional requirements for factory production control

EN 15804, Sustainability of construction works — Environmental product declarations — Core rules for

the product category of construction products

EN 15228:2009, Structural timber — Structural timber preservative treated against biological attack

EN 16485, Round and sawn timber — Environmental Product Declarations — Product category rules for

wood and wood-based products for use in construction

EN ISO 3166-1, Codes for the representation of names of countries and their subdivisions — Part 1:

Country codes (ISO 3166-1)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
dry-graded structural timber
timber for which grading has been completed after it has been dried
3.2
grading standard

a set of grading rules contained in a National Standard or a proprietary document that is publically

available
3.3
machine strength grading

process by which structural timber is sorted by a machine sensing, non-destructively, one or more

properties of the timber, with any necessary visual overriding inspection, into grades or strength

classes to which characteristic values of strength, stiffness and density may be allocated

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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)
3.4
package

structural timber of one grade, of one species or species combination, to be delivered to one customer

3.5
settings

values associated with the variable controls of a grading machine which determine the acceptance to

each grade or strength class of structural timber graded by the machine
3.6
strength class

result of the classification of structural timber based on particular values of its mechanical properties

and density
3.7
structural timber

timber with rectangular cross section strength graded either by visual means or by machine

3.8
strength-reducing characteristic

property or feature of a piece of structural timber that reduces its load bearing capacity

Note 1 to entry: Can result from natural growth of the tree (e.g. knots, slope of grain), changes in moisture

content (e.g. fissures), conversion of the log (e.g. the inclusion of wane), attack from fungi, insects or mechanical

damage.
3.9
timber source

identifiable geographical origin of a species or species combination from which timber is, or is intended

to be, strength graded
3.10
visual strength grading

process by which structural timber is sorted, by visual inspection and assessment, into grades to which

characteristic values of strength, stiffness and density can be allocated

Note 1 to entry: Electronic or mechanical instruments can be used to assist the visual grader in this process.

3.11
thickness
smaller dimension perpendicular to the longitudinal axis of a piece of timber
3.12
width
greater dimension perpendicular to the longitudinal axis of a piece of timber
4 Symbols
M machine graded structural timber
DG dry-graded structural timber
PT preservative treated structural timber
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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)
5 Requirements for structural timber
5.1 Mechanical resistance
5.1.1 General

Mechanical resistance covers modulus of elasticity, bending strength, compressive strength, tension

strength, shear strength and density.

Structural timber shall be either visually graded according to 5.1.2, or machine graded according to

5.1.3, and have characteristic values for the bending strength, tension strength, compression strength,

shear strength, modulus of elasticity and density according to 5.1.2 or 5.1.3. Characteristic values shall

be determined in accordance with EN 384.

If the structural timber is assigned to a strength class from EN 338, the characteristic values for the

properties shall be those given for the strength class in EN 338.

If the grading has been carried out before processing, provided that the processing reduction is not

greater than 5 mm for dimensions greater than or equal to 22 mm but less than or equal to 100 mm, or

not greater than 10 mm for dimensions greater than 100 mm, the grade shall be considered not to have

changed. If the reduction is greater, the structural timber shall be re-graded.

Structural timber that has previously been graded shall not be re-graded to the same or different grades

unless the method of determining characteristic values has made allowances for changes to the timber

population caused by the previous grading.

Since some geometrical characteristics (fissures, distortion) depend on the moisture content and affect

the strength properties, marking shall consider the moisture content at the time of grading.

Moisture content shall be determined in accordance with EN 13183-2 or EN 13183-3 with an accuracy

of ± 3 % moisture content (see Annex C).

Dry graded structural timber shall have at the time it is graded for fissures and distortion, a mean

moisture content of 20 % or less with no individual measurement exceeding 24 %.

If the grading method restricts the structural timber to a special use, e.g. flatwise bending or

compression, this shall be reflected in the marking.
5.1.2 Visual strength grading

Structural timber shall be graded visually in accordance with a grading standard which meets the

requirements given in Annex A. This grading standard shall be publically available.

If the grade and species or species combination have been assigned to a strength class by EN 1912, the

characteristic values for the properties shall be those given for the assigned strength class in EN 338.

Assignments according to EN 384 to be included in EN 1912 should be reported and evaluated by

CEN/TC 124. Accepted reports shall be documented in Approved Grading Reports (AGR).

NOTE Approved Grading Reports are intended to give basic documentation for the certification by a Notified

Body of a manufacturer's factory production control (FPC) needed for the CE marking. A current list of AGRs may

be obtained through CEN/TC 124 secretariat.

If there are any restrictions or additional criteria related to the strength or use of structural timber,

resulting from the method of grading or species or species combination, they shall be stated in the

grading standard.
5.1.3 Machine strength grading

For a grade and species (or species combination) graded by a machine control system, the settings shall

be derived for the total growth area from which the structural timber will be sourced.

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SIST EN 14081-1:2016+A1:2019
EN 14081-1:2016+A1:2019 (E)

Grading machines shall use settings determined in accordance with EN 14081-2. Grading machines and

settings used in machine control system should be evaluated by CEN/TC 124. Settings which have been

accepted by CEN/TC 124 shall be documented in Approved Grading Reports (AGR).

NOTE Approved Grading Reports are intended to give basic documentation for the certification by a Notified

Body of a manufacturer's factory production control (FPC) needed for the CE marking. A current list of AGRs may

be obtained through CEN/TC 124 secretariat.

The visual characteristics of each piece of machine graded structural timber shall meet the

requirements given in Table 1.

Table 1 — Visual override inspection requirements for machine strength graded structural

timber
Strength class according to C18, D18, T11 and below Above C18, D18, T11
EN 338
Max. length Fissures not
Fissures less than half the thickness may be ignored
going through
of fissures
Not greater than 1,5 m or 1/2 the length Not greater than 1 m or 1/4 the
the thickness
of the piece, whichever is the lesser length of the piece, whichever is
the lesser

Fissures going Not greater than 1 m or 1/4 the length of Only permitted at the ends with

through the the piece, whichever is the lesser. If at a length not greater than the

thickness the ends, a length not greater than two width
...

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